Magnesium alloy and method of making same



Patented Mar. 21, 1928.

UNITED STATES PATENT OFFICE. v

WILLIAM R. VEAZEY, OF CLEVELAND HEIGHTS, OHIO, ASSIGNOR TO THE DOWCHEMI- CAL- COMPANY, OF MIDLAND, MICHIGAN, A CORI'ORATION OF MICHIGAN.

MAGNESIUM ALLOY AND METHOD OF MAKING SAME.

No Drawing.

The present improved alloy is one in which magnesium is the predominantelement, the object being to develop an alloy that will possess thecharacteristic lightness which is obtained by the use of magnesium inexcess of eighty per cent, while such alloy will be characterized byhigh strength and toughness as well as possess a suflicient degreeofhardness. More particularly such alloy consists of magnesium and fromseveral hundredths to several tenths per cent of vanadium.

It has not been found feasible to heat the metals in ngestion togetherfor the purpose of alloying the same, since this will involve the use ofa temperature above the boiling point of magnesium, the melting point ofvanadium being approximately 1715 degrees centi-\ grade. By the presentimproved method, however, it has been foundpossible to produce alloys ofthese two metals containing substantial amounts of vanadiumcorresponding with theamount for instance employed in so-called vanadiumsteels and exercising a marked influence in the resultant product. Suchproduct having a vanadium content of less than one percent is for allpractical purposes no heavier than pure magnesium, which of course isvery much lighter than aluminum and the connnercial aluminum alloys; atthe same time if properly cast such alloy is of considerably greatertensile strength and impact-toughness without being unduly hard.

The invention then consists of anew product containing magnesium andvanadium in approximately the proportions stated, to-

gether with the steps involved in the making of such alloys hereinafterfully described and particularly set forth in the claims. The followingdescription it will be under-' stood thus sets forth but several ofvarious ways in which the invention may be carried out.

Briefly stated, the improved method of making the alloy in hand consistsin inter- .fusing a limited amount of a suitable vanadium compound'withan excess of magnesium whereby such compound is reducedto the metal andthereupon forms an alloy with the residuum of'magnesium still largelyexceeding the amount of the vanadium thus; reduced, from the compound-employed.

Application filed December a, 1924. sent; it). 754,484.

Preferably vanadium pentoxide (V,O,) is' employed, which compound may beprepared most conveniently from ammonium vanadate (NH,"VO,-). Suchpreparation is accomplished by igniting the vanadate and then fusing theresulting red-yellow powder in a suitable crucible, the resultingproduct ,being a red li uor which on solidifying becomes a dense ark redcrystalline substance, melting at about 680 degrees centrigrade.(Thorpe).

mass of molten magnesium is then prepared preferably using a flux ofslightly greater specific gravity than the molten metal and havingsufiicient surface tension to cause it to form a film thereover and thus4 prevent exposure of the metal to the .atmosphere; The vanadiumpentoxide is then added to such molten magnesium being pushed under thesurface thereof since it exhibits a tendency to float and if necessary 1a thorough inter-mixture of the oxide may be insured by stirring.However, the react1on-of the magnesium with the oxide occurs almostimmediately, the latter being reduced to metallic form and incorporatedin the mass of molten magnesium to form the desired alloy.

The molten alloy may then be conveniently removed from the crucible ormelting pot by means of an ordinary ladle and is cast into bars or suchother shapesas may be desired. .The amount of vanadium derived from anygiven quantity ofthe oxide is 56 per cent but some of this apparently islost in the reaction, at least less than the theoretical amount ofvanadium appears in the final alloy. However, the amount of oxide thatrequires to be added to give an alloy containing the desired number ofhundredths per cent of vanadium may be readily calculated, as need notbe explained in detail. The amount of such alloying ingredient actuallyintroduced may be checked by analysis using the method ordinarilyemployed in the analysis of chrome-vanadium steels. From three (3)one-hundredths'per cent to fifteen (15) one-hundredths per cent ofvanadium have been found to give most satisfactory results.

Other modes-of a plying the principleof my invention may a e employedinstead of the one explained, change being made as regards thecomposition and method herein disclosed, provided the ingredients orsteps stated by any of the following claims or the equivalent of suchstated ingredients or steps be employed.

I therefore particularly point out and distinctly claim as myinvention 1. As a new product, an alloy containing magnesium as thepredominant component and vanadium as a relatively smallmodifying-component.

2. As a new product, an alloy containing magnesium and Vanadium, whereinthe magnesiuni is the predominant component and the vanadium is presentin substantial amount but less than one per cent.

3. As a new product, an alloy consisting Ofq magnesium and from severalhundre'dths to several tenths per cent of vanadium; K

4:. As a new product, an alloy consisting of magnesium and approximatelyfifteen (l5) hundredths per cent of vanadium.

5. The method of making an alloy of vanadium with magnesium, whichconsists in interfusing with an excess of magnesium an amount of avanadium compound adaptmetallic vanadium is ed to be reduced to metallicalloy state in the magnesium.

"6. The method of making an alloy of vanadium with magnesium, whichconsists in interfusing with an excess of magnesium an amount ofvanadium pentoxide to be reduced to metallic'state in the magnesium.

7. The method of making an alloy of vanadium with magnesium, whichconsists in adding to a body of magnesium in molten state an amount ofvanadium compound in excess of that required to reduce such compound,whereby the desired proportion of metallic vanadium is alloyed in suchmagnesium.

8. The method of making an alloy of vanadium with magnesium, whichconsists in adding to a body of magnesium in molten state an amount ofvanadium pentoxide in excess of that required'to reduce such compound,whereby the desired proportion of alloyed in such' magnesium. I

Signed by-me, this 4th dayof.December, 1924.

WILLIAM R. VEAZEY.

